Closure for slotlike apertures



Patented Oct. 5, 1943 FED STATES PATENT OFFICE CLOSURE FOR SLOTLlKEAPERTURES Louis W. Schaai, Jackson Heights, N. Y., assignor to WaldesKoh-I-Noor, Inc., Long Island City, N. Y., a corporation of New YorkApplication November 6, 1941, serial Ne. 418,083

6 Claims.

This invention relates to closures for slot-like apertures and moreparticularly to a closure for the slot-like aperture of a machine gunturret.

As usually constructed, machine gun turrets are provided with avertically disposed aperture through which the barrel of the gunprojects and along which it moves vertically when elerubber flapsdisposed in overlapping relation along the aperture and arranged to openabout the gun barrel as the latter is moved therealong. This type ofclosure, while satisfactory at low plane speeds, has developed theserious disadvantage that at the higher plane speeds when the air flowpressures are great, the rubber flaps tend to collapse and to push intothe aperture in such manner that they not only fail to serve theirintended purpose as a closure but also interfere with the freeelevational movement of the gun barrel.

The present invention contemplates and provides an improved closure forthe gun barrel aperture of turrets, such as machine gun turrets, whichpermits of free movement of the projecting gun barrel along theaperture, which maintains the aperture closed above and below and alsoaround the gun barrel, and which is unaffected by air ow pressures whichtend to collapse and/or impair the functioning of the prior turretclosures. More specifically, the invention seeks to provide an eliectiveclosure of the slide fastener type for the gun barrel aperture of amachine gun turret, which is operable by the gun barrel itself and whichis so arranged as to provide a closure opening for the projecting gunbarrel While maintaining the aperture portions above and below the gunbarrel closed, regardless of the elevation of the barrel, i. e., itsangle of inclination from the horizontal.

The invention also makes provision for the free elevational movement ofa gun barrel along an aperture therefor as formed in a turret wall whichcurves along an arc which is different from the are of movement of thebarrel or which ex' tends straightway in a vertical plane or straightwayin an inclined plane.

Among the further objects of the invention may be noted the provision ofa slide fastener closure for an aperture of the stated character whichis simple in design and sturdy in construction, which is easy toassemble and disassemble, and which is sure andcertain in lts operation.

Other objects will be in part obvious and in part hereinafter pointedout in connection with `close the aperture II while permitting the gunbarrel to extend therethrough and providing for.

(Cl. 1GO-368) the following analysis of this invention wherein` isillustrated an embodiment of the invention in detail.

In the drawing- Fig. 1 is a partial front elevation of the closure meansof the present invention as applied to the gun barrel apertureof amachine gun turret;

Fig. 2 isa section taken along line 2 2 of Fig. 1;

Fig. 3 is a broken-away side elevation of the turret and closure meanstherefor as illustrated in Fig. 1;

Fig. 4 is a sectional elevation taken through the slider carriage andwhich illustrates thecarriage guide means.

Fig. 5 is a section taken -through the relatively upper sliderillustrated in Fig. -1;

Fig. 6 is a section taken through the relatively lower sliderillustrated in Fig. 1.

Referring to the drawing, wherein like reference characters designatelike parts throughout the several views, reference character I0generally designates a machine gun turret of approved construction', thedetails of which willvnot be described here as the turret per se formsno part of the present invention except insofar as it nters into thecombinations hereinafter claimed.

As shown, the turret has a side wall which exy tends straightway and isinclined from the vertical, being provided with a vertically disposedslot or aperture Il through which the barrel l2 of a machine gun mountedwithin the turret is adapted to project'and along which the barrel ismoved inits elevational or lowering movement. Depending on particulardesign requirements, the turret side wall may be vertically disposed, orit may extend along a curvature which corre. sponds with or isdiierentfrom the arc of movement of the gun barrel, it being here notedthat in the case of the vertical or straightway inclined turret sidewall and also where the side wall extends along a curvature which isdiiferent from the arc of movement of the gun barrel, the latter movesrelatively inwardly and outwardly through the aperture Il as it iselevated and lowered.

According to the present invention, closure means of the slide fastenertype, and which-embodies principles disclosed and claimed,I in myapplication entitled .Slide fasteners, Serial No. 420,284, led November24, 1941, are employed to free movement of the gun barrel along theaperture. As shown, the improved closure means is formed by two apelikestringers I5, I6, each secured along a. side edge of the aperture and tothe under face of the turret casing by a securing strip I'I held inplaceby rivets I8 or equivalent securing devices. AThe stringers arefabricated from heavy waterproof canvas, and each extends approximatelyhalfway across the aperture. The stringers carry along their inneradjacent edges a chain of fastener elements 28.01? conventionalconstruction, which are adapted to be embraced by a lower slider 22 andan upper slider 23, the upper slider being reversed with reference tothe lower slider.

The sliders 22, 23 are spaced from each other vertically a fixeddistance which is slightly greater than the diameter of the gun barrell2. The function of the lower slider, which operates with the chain, isto effect the engagement of disengaged-fastener elements disposed belowthe barrel as the latter is moved upwardly and the disengagement ofengaged fastener elements below the barrel as the latter is moveddownwardly. Due to the reversed relation of slider 23, the latteroperates against the chain to effect the disengagement of engagedfastener elements above the barrel as the latter is moved upwardly andthe engagement of disengaged fastener elements above the barrel when thelatter is moved downwardly. The spacing between the sliders 22, 23provides an opening through the fastener for the gun barrel I2, which ismaintained in all positions of the barrel, as well as during movement ofthe barrel along the aperture.

The operation of the sliders 22 and 23 is illustrated in Figs. 5 and 6for fastener elements whose locking teats or projections are upwardlydisposed, it being understood that the illustrated slider arrangementwhich is capable of effecting two-way operation of the fastener willpermit the reversal 0f fastener elements, in which case the lockingprojections thereof are pointed downwardly.

Referring to Fig. 6, the Wedge or divider 25. of the lower slider 22which operates with the chain may be of the type having a bluntlyrounded operating end providing an obtuse spreading angle for theelements, against which the locking pro.- jections 2,6 and the end faces21 of the fastener elements are adapted to bear as the elements arespread fanwise in moving into the race branches of the slider.

The relatively reversed slider 23 has its divider 30 also formed with abluntly rounded Working end which is purposely so shaped as to providethe required obtuse spreading angle for the elements necessary to thefree operation of the slider when the latter is operated against thechain, said working end presenting a definitely curved or roundedsurface against which the more or less straight end'faces as well as thesquared under corners 28 of the elements are adapted to bear as thedivider spreads the elements fanwise into the race branches of theslider. The arrangement is thus such that as sliders 22 and 23 are movedupwardly, the lower slider 22 operates to progressively engage and theupper slider 23 to progressively disengage the fastener elements abovethe same. As the sliders 22 and 23 are moved downwardly, they effectreverse operation of the fastener. Thus, the twoway operation isindependent of the direction in which the locking projections face.

The sliders are carried in vertically aligned relationship by a slidercarriage generally designated 35 as illustrated in side elevation inFig. 3, and in sectional elevation in Fig. 4. As shown, the carriagetakes the form of a substantially rectangular frame having vertical sidepieces 36, 31 secured in spaced relation by a top cross piece 38 and abottom cross piece 39 through securing screws 40. 'Ihe top cross piece38 carries an angled downward extension 42, to which the upper slider 23is secured as by welding or riveting. Similarly, the bottom cross piece39 of the frame carries an angled upward extension 43, to which thelower slider 22 is secured as by welding or riveting. As seen in Fig. 4,the barrel projects through the carriage and, as will appear from Fig.3, the latter secures the sliders in spaced vertical alignment on themuzzle side of the barrel.

To insure free relative movement between the carriage and barrel, asrequired whenthe turret side wall extends straightway or along an arcwhose curvature is diierent from the arc of movement of the barrel, thecarriage is provided with bearing means whereby it may freely moveaxially of and along the barrel as the latter is elevated or lowered.Suchbearing means preferably takes the form of upper and lower concavedbearing rollers 44, 45 of non-metallic anti-friction material such asvulcanized fiber, the rollers being arranged to bear against and roll onthe gun barrel. The upper roller 44 is mounted in the carriage framethrough the medium of angled mounting brackets 46, 41 held in placewithin the frame by dowel pins 48. The horizontal anges of the angledbrackets 4are disposed in horizontal alignment, the vertical legs orflanges being spaced to provide a journal mounting for the spindle 50carrying the bearing roller. The lower bearing roller 45 is mounted inthe carriage frame through the medium of angularly disposed bearingbrackets 52, 53 secured to the frame in similar manner by dowels 54,.inthe vertical flanges of which the roller spindle 55 is journaled.

The carriage 35 is guided for vertical movement along the aperture byspaced guide rods 51, 58 which extend adjacent the aperture edges andare preferably disposed within the turret enclosure. The rods may besecured in xed relation by top and bottom brackets (not shown) carriedby the turret. Guide collars 59, 60, each provided with a wear sleeve 6Ipreferably of nonmetallic bearing material such as vulcanized fiber, arearranged to slide on the guide rods and are connected with the slidercarriage by swivel pins 62, 63 which extend sidewardly from the carriageinto guide collar sockets 64, 65. Preferably, the pins seat in wearbushings 66 of nonmetallic bearing material carried by the collarsockets.

Due to the swivel mounting of the slider carriage in the guide collars59, 60, the carriage may tilt on the axis of the pins 62, 63 as requiredto accommodate itself to the curvature along which the barrel apertureextends, if any.

By reference to Figs. 1, 5 and 6, it will be appreciated that thedisengaged fastener elements of the fastener portion extending betweenthe sliders 22, 23 tend to curve around and crowd against the gunbarrel. While such an arrangement is advantageous in that a closure iseffected directly around the barrel, a feature never before vcompletelyachieved, it is desirable that the fastener elements do not beardirectly on the barrel. Accordingly, the carriage 35 carries arcuatelyextending guide tracks 68, 69 which are disposed sidewardly of the frameopening for the gun barrel and in which the disengaged fastener elementstrack as they curve around the barrel. Each track is provided with anelement receiving groove 10 which is disposed in alignment with thesliders 22, 23. Hence, the disengaged fastener elements insteadof'bearing directly against the gun barrel as they curve or move aroundthe barrel travel in the curved guide tracks in the manner illustratedin Fig. l. In addition to providing denite guidance for the disengagedfastener elements as aforesaid, the tracks, when fashioned fromnon-metallic anti-friction material as contemplated, prevent undue wearof the elements which is likely if the latter bear directly on the gunbarrel and further insulate the fastener from the heat of the gun barrelgenerated as a consequence of the rapid firing of the gun.

While in the foregoing description, the closure aps are constituted bythe fastener stringers, it will be understood that-closure flaps of moreor less conventional construction may be used, to the adjacent edges ofwhich separate stringers carrying the fastener elements may be secured.

It will further be understood that while fastenerv elements having theirlocking projections upwardly disposed have been illustrated, the ar.-rangement may be reversed so that the fastener projections pointdownwardly, in which case the arrangement of sliders would also bereversed.

Without further analysis, it will be-seen that the present inventionprovides an improved closure of the slide fastener type for a slot-likeaperture such as the gun barrel aperture of a machine gun turret. Suchan improved closure insures that the aperture is at all times maintainedclosed both above and below the barrel, regardless of its position inthe aperture or its angle of inclination. Moreover, a closure asdescribed is substantially unaifected by the high air ow pressuresresulting from high plane speeds, and accordingly protects the gunnerfrom air blasts entering the turret through the aperture and frominclement weather. It is a further important feature of the inventionthat the slider assembly is adapted for operation by the, gun barrelitself and that the fastener is accordingly operated in automatic mannerin response to movement of the gun barrel.

While in the foregoing description the invention has been described inits application to the closing of the gun barrel aperture of a machinegun turret, along which the gun barrel is freely movable, it will beunderstood that the invention has wider application to the closing ofany slotlike aperture through which a member projects and along whichthe member is movable.

As many changes could be made in carrying out the above constructionswithout departing from the scope of the invention, it is intended thatall matter contained in the above description or shown in theaccompanying drawing shall be interpreted as illustrative and not in alimiting sense.

I claim:

1. In a closure for a slot-like aperture, a pair of closure flapscarrying fastener elements along their adjacent edges, two spaced andoppositely arranged sliders cooperating withsaid elements to provide ashiftable opening through the closure while maintaining the fastenerelements closed on both sides of the opening, and a framelike carriageproviding a mount for and xedly securing the sliders in their necessaryspaced relationship, the carriage being` provided with means to guidethe disengaged elements around said opening, and with means adapted tocooperate with guide means arranged along the edge of the aperture forguiding `the carriage along the latter.`

2. In a closure for a slot-like aperture, a pair of closure flapscarrying fastener elements along their adjacent edges, two -spaced andoppositely arranged sliders cooperating with said elements to provide ashiftable opening through the closurewhile maintaining the fastenerelements closed on both sides of the opening, and a framelike carriageproviding a mount for and iixedly securing the sliders in theirnecessary spaced closed on both sides of the'opening, and a frame..

like carriage providing a mount for and xedly securing the sliders intheir necessary spaced relationship, the carriage being provided withoppositely curved track sections defining said opening and which areoperative to guide the disengaged fastener elements between saidsliders, and with means adapted to cooperate with guide means arrangedalong an edge of the aperture for guiding the carriage along the latter.

4. In a closure for a slot-like aperture, a pair of closure flapscarrying fastener elements along their adjacent edges, two spaced andoppositely arranged sliders cooperating with said elements to provide ashiftable opening through the closure while maintaining the fastenerelements closed on both sides of the opening, and a framelike carriageproviding a mount for and xedly securing the sliders in their necessaryspaced relationship, the carriage being provided with rollers adapted tobear on a member extending through said opening.

5. In a closure for a slot-like aperture, a pair of closure flapscarrying fastener elements along their adjacent edges, two spaced andoppositely arranged sliders cooperating with said elements to provide ashiftable opening through the closure while maintaining the fastenerelements closed on both sides of the opening, and a frame-like carriageproviding a mount for and xedly securing the sliders in their necessaryspaced relationship, the carriage being provided with guide rollersadapted to bear on a'member extending through said opening and saidcarriage carrying means adapted to cooperate with guide means arrangedalong an edge of the aperture. A

6. In a closure for a slot-like aperture, a pair of closure. apscarrying fastener elements along. their adjacent edges, two spaced andoppositely arranged sliders cooperating with said elements to provide ashiftable opening through the closure while maintaining the fastenerelements closed on both sides of the opening, and a framelike carriageproviding a mount for and iixedly securing the sliders in theirnecessary spaced relationship, the carriagerbeing provided with opingand guide ears adapted to cooperate with guide means arranged along anedgeof the aperture.

LOUIS W. SCHAAFF.

